Spurred by the pressures of paper-based checking which is costly and time consuming for financial institutions and further in light of the inconvenience of maintaining accurate accounting in cash transactions, institutions have sought out and experimented with various electronic means of extending and speeding up account accessibility. To this end and to improve record keeping as well as to reduce flow of actual cash, computer technology has been applied to develop electronic funds transfer, which essentially is a process of value exchange achieved through electronic devices. Examples of electronic funds transfer equipment that have become used on a substantial basis in recent years are the Automated Clearing House (ACH), the Automated Teller Machine (ATM) and the point of sale system (POS).
To eliminate the presence of a central computer in every transaction, there has been a trend toward off-line electronic funds transfer, that is, transfer of data between portable and resident units, with only periodic downloading of data to a central computer. In Mareno U.S. Pat No. 4,007,355, for example, cashless transactions are made between credit cards through a special interface located at each vendor station. Stuckert U.S. Pat. No. 4,277,837 is directed toward a cashless, off-line transaction system involving portable units that are carried by customers and adapted for use with data storage and transfer cards.
The Mareno and Stuckert systems have particular problems that have limited their widespread use in off-line electric funds transfer. In Mareno, no exchange of funds may be made arbitrarily because the cards carried by each user, although having funds data storage capability, have no keyboards and require a special interface apparatus to be present at each transaction. In Stuckert, cards used with the portable terminals have no display; a separate portable terminal must be involved during each transaction. The user cannot continuously monitor his account, limiting the versatility of the system.
These problems and others were solved by Benton in U.S. Pat. No. 4,305,059 issued on Dec. 8, 1981, disclosing a modular funds transfer system wherein each user as well as vendor carries an identical portable module having a keyboard and a display Funds are transferred between modules using a hard wire interface, and the account status stored in each module is updated following each transaction. In another patent to Benton U.S. Pat. No. 4,341,951, printed vouchers are issued by the portable module following each transaction.
The Benton approach was further refined in U.S. Pat. No. 4,454,414 to provide bidirectional optical coupling between portable funds data transfer modules, including a "hand-shaking" protocol that enables funds transfer to be completed only if a number of criteria are satisfied. These criteria include an identification check following keyboard entry by the user of a secret number and examination of the transaction amount to ensure that it falls within.
Finally, in Benton et al. U.S. Pat. No. 4,625,276, electronic funds data are transferred between portable modules either directly in a local mode of operation or indirectly, via telephone lines, in a remote mode of operation Transaction records are printed by an outboard printer or downloaded to a central computer.
The systems described in the aforementioned Benton et al. patents are capable of having a substantial impact on the manner by which financial transactions are carried out, securely transferring funds between buyers and sellers while simultaneously printing supporting documents. However, considerable dedicated apparatus including a modem and printer as well as portable modules are required to implement these systems The present invention provides on-line electronic funds transfer in a manner to reduce the cost of implementation, and to improve availability, of the system to the parties of a transaction.
There currently are more than two million facsimile machines throughout the world, used exclusively for the transfer of documentary information between individual stations connected to any dial up telephone line. Such machines, with printer and keypad as well as a modem, are capable of transmitting and receiving graphical data, e.g., bit mapped images as well as textual data In copending application Ser. No. 236,614 to Benton et al., filed Aug. 23, 1988, there is described a modification to and implementation of a conventional facsimile machine to be operative in a transaction mode of operation for carrying out transactions between buyers and sellers. The Benton et al. system in '614 incorporates a keyboard in the facsimile machine together with special identification modules each containing an integrated circuit memory storing account data, and, in graphical form, the signature of an authorized user During transactions, the facsimile machine transmits ASCII characters corresponding to keyboard entered transaction data such as the amount of the transaction together with account and signature data to another facsimile machine similarly configured and containing the identification module of the other party to the transaction. Following agreement between the parties, funds are exchanged, the integrated circuit memories in the identification modules are updated by the amount of the transaction, and the facsimile machines print transaction records including the signatures of the parties Occasionally, the contents of the identification cards are downloaded to a central computer at an automated clearing house (ACH) for account updating.
While generally satisfactory, the Benton et al system just described requires modification of existing facsimile machines to interface with the integrated circuit memory modules carried by authorized users. System implementation would be substantially simplified if electronic funds transfer could be carried out through conventional, unmodified facsimile machines It would also be preferable to clear transactions at the ACH in real time, on line, in a manner consistent with existing funds transfer protocols.